RPM spikes & duty cycle drops

[zuki1018]

Running MS1v3. 1.6ltr Geo Tracker motor with a T25 Saab donor turbo.

Hoping an expert tuner or two could take a quick look at my log file. Right out of the gate at a time of about 675 you can see rpms jump from 24xx up to 63xx as boost is starting to build. Pretty fast afterwards the PW drops to 0.

A tad up at time of 684 boost is quite a bit higher... duty/PW goes to 0. I do realize the fuel table jumps from 99 to 115.

My best guess is that I am running out of fuel. Stock injectors from all i have found on the net are rated at 175cc. Stock fuel pressure regulator.

Maybe you have seen some similar symptoms to point me in a direction or two?
Thanks a lot in advance.

[Matt Cramer]

What exactly are you using for RPM input?

[zuki1018]

What exactly are you using for RPM input?

Thanks for the response Matt.

Input using a crank mounted 36-1 wheel with 3-wire hall. Output to the factory internal coil dizzy. Another (deleted) recent log file had a max RPM spike of like 15,000.

[zuki1018]

So the more log files I look at, the more it looks like an RPM spike/sync issue.



Im not sure whats causing that additional smaller tooth reading. The hall is a new one from DIY. The truck ran great pre-turbo install. I am guessing I was getting sync issues pre-turbo ...but they weren't as apparent.

EDIT: I just noticed the batt voltage at time of 697 drops to 11.3

New battery, new alternator ...sigh.

[Matt Cramer]

The slightly longer tooth shouldn't make the MS1/Extra wheel decoder lose sync. Can you post a tooth log of when the problem is happening?

[zuki1018]

Sure... I did a tooth and datalog at the same time last night. I have lite version of all software so its hard to interpret tooth logs in excel to compare.

[Matt Cramer]

Hard to say for sure if anything in that log should make you lose sync. How is the RPM input circuit set up?

[zuki1018]

Thanks for staying with me.

Its been so long i cannot remember.

Would it help narrow things down if pulled my MS box to upload a front/back picture? I do remember going back/forth with my dizzy on low to high, high to low. Not sure if having that backwards would cause these spikes or cause something more major.

Also I found a topic on keeping shielded pair away from high current wires. I realize that mine do go into my wire loom at the firewall and are 'somewhat' close before my 12v supplys (to hall, injectors, & coil) branch off to the battery and the shielded pair go through the firewall to MS.

[Fastspec2]

Are you still useing a distributor?

[zuki1018]

Are you still useing a distributor?

Yes, factory internal coil on the G16 engine.

[Matt Cramer]

Thanks for staying with me.

Its been so long i cannot remember.

Would it help narrow things down if pulled my MS box to upload a front/back picture? I do remember going back/forth with my dizzy on low to high, high to low. Not sure if having that backwards would cause these spikes or cause something more major.

Also I found a topic on keeping shielded pair away from high current wires. I realize that mine do go into my wire loom at the firewall and are 'somewhat' close before my 12v supplys (to hall, injectors, & coil) branch off to the battery and the shielded pair go through the firewall to MS.

If you don't know, I strongly recommend opening the box and finding out.

The 12 volt supply wires are not very high current except the coil wire.

[zuki1018]

The G16 has low impedance injectors if that may open up some avenues of suggestion.

Input: 36-1 crank wheel with DIYauto hall. Pretty sure i added a 1k resistor when i wired it in.
Output: looks like I chose Low to High, then 5v

R12 has resistor
Removed C30 and ran the top side to 5v on proto

Here is the front/back picture
http://www.driftwoodchimes.com/zuki1018/Pix/052112122417.jpg

http://www.driftwoodchimes.com/zuki1018/Pix/052112122352.jpg

[Matt Cramer]

Try jumpering it for VR input, and use more solder.

[zuki1018]

Try jumpering it for VR input, and use more solder.

So you mean to remove :
TSEL to OPTOout
TACHSELECT to XG1

And jumper:
TSEL to VROUTInv
TACHSELECT to VRIN

[zuki1018]

Done.

So far no spikes during idle/warm-up. Will do some driving logs later this evening. Thx.

[zuki1018]

I only had time to drive around once last night.

Around 538 my rpm spiked to 22,000. I believe this is when my transfer case popped into neutral while shifting. Theres also something a bit corkey around 615.

Overall so far ...so better. I dont see any irregular rpm spikes other than the 1 major one. I ended up blowing a U joint last night. These trucks weren't made to have twice the torque and large tires.

What does the VR circuitry do differently over the Hall?